3
The Sun is the most energetic particle accelerator in the solar system: - Ions up to ~ 10s of GeV - Electrons up to ~100s of MeV Acceleration occurs in transient energy releases, in two (!) processes: - Large Solar Flares, in the lower corona - Fast Coronal Mass Ejections (CMEs), in the inner heliosphere, ~2-40 solar radii

49
Above-the-loop-top HXR source limb thermal loop HXR footpointsHXR above the loop top source YOHKOH HXT observations: Only very rarely seen! 6 good events in 10 years. The most famous one is the so-called Masuda flare (Masuda et al. 1994)